1. Field of the Invention
This invention relates to managing storage systems, and more particularly to apparatus and methods for managing storage groups in storage systems.
2. Background of the Invention
System-managed storage (SMS) refers to applications or programs that enable an operating system to take over many of the tasks of managing storage, tasks that were previously performed manually by systems programmers. When configuring an SMS application, a storage administrator may define classes of storage and rules designating how data sets are allocated to these classes of storage. Once the SMS application is properly configured, the SMS application may automatically perform tasks such as allocating data sets to appropriate storage volumes, backing up the data sets, managing space in the storage volumes or groups of storage volumes, and migrating older data sets to less expensive forms of storage.
SMS applications are important to keep storage costs down and ensure that storage is used efficiently. The costs of storage may include not only the initial cost to purchase the storage, but also costs of electricity to operate the storage, facilities to house the store, and personnel to install, monitor, and/or manage the storage. Although removable media such as optical and tape storage may cost less per megabyte than other types of storage, this type of media may require additional time and resources to locate, retrieve, and mount. Considering all the costs, SMS applications play an important role in controlling and managing storage so a business can grow and expand in a profitable manner.
Currently, most SMS applications use predefined pools or groups of virtual storage devices (e.g., virtual volumes) to store data. These groups are generally static, although system administrators can typically manually add or delete volumes from these groups when needed. The problem with managing storage in this manner is that the amount of storage required by applications using a storage group can vary significantly over time. That is, the amount of storage space required by applications can go up during certain periods of time, and down during other periods of time. Furthermore, these time periods can differ for different storage groups. This makes it difficult to effectively manage the space in storage groups and ensure that storage is allocated in an efficient manner over different periods of time.
In view of the foregoing, what are needed are apparatus and methods to effectively manage space in storage groups. Ideally, such apparatus and methods could automatically increase the space in storage groups during certain periods of time while reducing the space during other periods of time. Further needed are apparatus and methods to tailor the amount of space in a storage group to the particular application or applications using the storage group.